The invention is directed to a quick release valve for a sprinkler head wherein a thermal responsive actuating element such as a frangible bulb, link, lever, fusible alloy strut or the like is used as the triggering element. The sprinkler head is coupled to a conduit which provides a pressurized fluid, such as water for extinguishing a fire.
A sprinkler head wherein the compressive preload on the thermal responsive element is reduced without substantially compromising the valve seal is disclosed in U.S. Pat. No. 4,167,974 (Job). The temperature responsive element is a frangible bulb mounted between the head body and a preloaded Belleville washer mounted on the valve seat. The preloaded washer flexes to accommodate fluid pressures experienced during normal operation.
A quick release valve for a sprinkler head wherein the compressive preload on a frangible bulb is substantially reduced is disclosed in co-pending patent application Ser. No. 722,084 filed Apr. 11, 1985 in the name of the inventor herein and assigned to the same assignee. Reduction of the compressive preload allows lightweight and thinner walled frangible bulbs to be employed so as to provide a quicker response or triggering action without compromising the frangible bulb or the valve seal.
The problem solved by the present invention is that of providing a self-sealing quick release valve for a sprinkler head which exerts minimal compressive preload and load on the thermal responsive actuating element whereby the element as well as the sprinkler head frame can be made thinner and lightweight without compromising the integrity of the element or the valve seal and the conventional set screw for compressive preload can be eliminated.